Facsimile apparatus



April 1942- G. L. ERICKSON ETAL 2,273,919

FACSIMILE APPARATUS 4 Sheets-Sheet 1 Filed March 25, 1939 W .J s R m Y #9 m mu M Q: N R R EEW O m l QR A o M April 7, 1942- cs. L. ERICKSON ETA L 2,278,919

FACSIMILE APPARATUS Filed March 23, 1939 4 Sheets-Sheet 2 FIG. 2

INVENTORS G.| ERIGKSON R.J. WISE ATT RNEY Patented Apr. 7, 1942 FACSIMILE APPARATUS George L. Erickson, Hasbrouck Heights, and Raleigh J. Wise, Dnnellen, N. 1., assignors to The Western Union Telegraph Company, New York, N. Y., a corporation of New York Application March 23, 1939, Serial No. 263,632

16 Claims.

The present invention relates to the transmission and reception of pictures, messages and other subject matter in facsimile and more particularly to novel and improved means for transmitting or reproducing a facsimile of, transmitted subject matter. t

The primary object of the invention is to provide an improved multi-stylus facsimile machine of the continuous type in which the styli are guided and moved along a common path in a novel manner.

Another object of the invention is to provide novel means for imparting movement to a stylusor a plurality of styli in a facsimile machine of the type in which a stylus traverses a given path during a scanning movement and a separate return path in the intervals between scanning movements.

A further object of the present invention is to. provide novel means for accurately locating a plurality of styli in a desired position on a movable conveyor.

Still another object of the present invention is to provide improved means for supporting and propelling a record sheet of any length in a facsimile recording machine.

A further object of the present invention is to facilitate maintenance and repair of facsimile recorders by having the improved parts thereof assembled into separate interchangeable units which may be handled and serviced separately.

Other and more specific objects of the invention are defined by the terms of the appended claims and will be apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a top plan view partially sectioned on line ll of Fig. of a recorder embodying the invention;

Fig. 2 is a left side elevation of the embodiment of the recorder shown in Fig. 1;

Fig. 3 is a view in sectional elevation taken on line 3-3 of Fig. 1;

Fig. 4 is an enlarged fragmentary view of a detail of the paperfeeding mechanism;

Fig. 5 is an enlarged sectional view taken on line 55 of Fig. 1, as viewed in the direction of the arrows illustrating inventive features of the stylus supporting and driving unit;

Fig. 6 is an enlarged bottom plan view par tially in section and illustrates details of a stylus holder and stylus;

Fig. 7 is an enlarged top plan view of a stylus holder and stylus;

Fig. 8 is a side elevation partially in section of a stylus holder and stylus;

Fig. 9 is a view in plan illustrating the method of mounting the styli;

Fig. 10 is a view in plan of a fragmentary part of Fig. 9 drawn to an enlarged scale;

Fig. 11 is an enlarged fragmentary sectional elevation taken on line ll-ll of Fig. 9; and

Fig. 12 is an enlarged fragmentary section taken on line I2I2 of Fig.1i.

Referring now more particularly to Fig. 1, the apparatus embodying the invention and designed for recording comprises a base l0 upon which are mounted two separate units indicated generally by reference characters H and I2 respectively, the former embodying the stylus support and driving mechanism, and the latter the paper supporting and advancing mechanism.

The paper carrying and feeding unit [2 now to be described in detail comprises a sub-base ll (Fig. 3) which is secured to the base It by suit able fastening means such as screws l5. A plate member l6 resting upon the sub-base H is provided with similar upright frame members I! and I8 in which a shaft I9 is journaled having secured thereon pulleys 2|, one adjacent each upright member. An idler pulley 23 is mounted for rotation on a stub shaft 26 secured to the frame member I3 and a like pulley 23 is mounted in a similar manner from the frame member l1. Short flexible belts 23 pass over each set of pulleys 2| and 23 and project through openings formed in the combined guide member and platen 29 which is of a U-shape as shown in Fig. 3 and is carried by the frame members I! and [8 to which it is secured by suitable fastening means. A strip of smooth material 3|, preferably glass, which has the advantage of being transparent, is pressed against the belts 23 by means of two pairs of spring fingers 32, one pair being secured to the frame member I1, and the other pair being secured to the frame member l8. A record sheet or web 33 is drawn from a rotatably mounted supply roll 34 which is carried by oppositely disposed pins 36 secured to the rearwardly extending arms 31 of the U-shaped member 33. A set screw 39 for each pin 36 permits it to be readily adjusted, and a spring mounted friction member 40 carried by one of the arms of the member 38 prevents a too rapid unwinding of the roll 34. The web 33 is drawn over the platen portion 4| of the member 23 by its frictional engagement with the belts 28 which are moved at the proper speed to space the scanning lines in a manner now to be described.

Driving power is imparted to the shaft 18 for moving the belts from a gear 42 through a ratchet clutch mechanism comprising clutch members 43 and H. The gear 42 is secured to the clutch member 43 which in turn is journaled on the shaft is to rotate freely thereon as shown in detail by Fig. 4 of the drawings. In order that the paper web 33 may be advanced manually at any time and independently of the driving ear 42, the shaft I3 is extended outwardly beyond the frame member l3 and terminates in a conveniently accessible knob 45 (Fig. 1). Upon the knob 45 being turned manually in a clockwise direction as viewed from the right hand side of the apparatus, the previously mentioned ratchet clutch comprising the members 48 and 44 slips by reason of the ratchet form of the intermeshing teeth 48 on the clutch members 48 and 44. The clutch member 44 drives the shaft I9 from the clutch member 49 through a sleeve 41 which is secured to the end of the shaft by means of a set screw 48 and the clutch member 44 is constrained to turn with the sleeve 41 by means of a pin 49 engaging an axial slot 58. A compression spring I tends to maintain the clutch teeth in engagement.

The gear 42 meshes with an idler pinion 52 (Fig. 2) rotatably carried by a stub shaft 53, the latter being mounted upon an auxiliary frame member 54. The frame member 54 is carried by and spaced from the frame member I1 by means of three studs or equivalent fastening means 55. The idler pinion 52 is driven by a pinion 55 secured on a shaft 51 journaled on the auxiliary frame member 54. A worm wheel 58 is secured to the shaft 51 and is in meshing engagement with a driving worm 59 carried by a shaft 58 which is joumaled in a bearing 5| on a horizontal extension 52 of the auxiliary frame member 54. The shaft 58 extends forwardly toward the stylus carrying unit II beyond the worm 59 and is provided with an overrunning clutch 88 of the free-wheeling" type. The driving member 54 of the clutch 53 is hollow and is slotted as indicated at 55 to accommodate a driving pin 55 secured adjacent the end of a shaft 51 extending from the stylus carrying unit II later to be described. It will be noted that the slots 55 and the pin 55 together form a quick detachable clutch member which is conveniently engaged when the unitary structure II is placed in operative position upon the base I8.

An auxiliary high speed motor 58 secured to the base I8 isconnected to the shaft 58 by means of any suitable flexible coupling such as that illustrated at 59. The motor 58 is connected to any suitable power source by conductors I8 (Fig. 1). A switch H which may be manually operated is provided so that the paper web 38 may be advanced at a high speed independently of the synchronous driving mechanism of the unit II, the clutch 58 permitting this accelerated movement of the paper. It will be understood that the switch 1I may be an automatically operated means, such as that disclosed in the copending application of Parrett et al., Serial No. 161,358, filed August 28, 1937, controlled by marks, indentations or apertures in the paper or by automatic means such as that disclosed in the copending application of Ridings et al., Serial No. 264,512 filed March 28, 1939. In this latter application is disclosed and claimed an arrangement for spacing the recording web from the styli, which is desirable when the web is moved rapidly and is necessary when the styli are moving and the web isstationary. This latter condition will exist whenthe recorder is arranged, by the inclusion of a clutch or otherwise, to stop feeding of the web while the motor I I8 continues to operate at scanning speed, as will hereinafter appear. 7

The space between frame members I1 and I8 which lies beneath the lower wall of the papercarrying guide 29 is enclosed to form a chamber 12 by means of a sloping top wall member 18 and front and rear wall members 14 and 15.

0 casing 99 by a web member I8I.

These three wall members are secured in a suitable manner as shown at 11 and 18 to the frame members I1 and I8 and the rear wall member 15 is apertured to receive a connection member 88 for a hose or other conduit 82 which is in communication with the interior of the chamber 12 formed by the wall members 18, 14 and 18.

The portion of the wall member 14 adjacent to the platen section 4| of the paper holder 29 is bent outwardly as indicated at 84 so that its upper edge lies closely adjacent the line of travel of the several styli. This provides a narrow elongated opening through which dust or fumes liberated during recording may be drawn into the chamber 12 for ultimate disposal by way of the conduit 82 which is in communication with a suction blower and filter or other suitable device (not shown) to be found in the prior art.

The sub-base I5 of the unit I2 which, as previously stated, is slidably mounted upon the base I4, is adjustably positioned by means of a pair of shafts 85 and 81 threaded as indicated at 88 and 89 to engage blocks 9I secured to the subbase I5 adjacent the members I1 and I8 respectively and each provided with a threaded recess for the purpose. The shafts 85 and 81 are each provided with a hand wheel 92 situated at a convenient point beyond the paper supply roll 34 and these hand wheels may be operated simultaneously to move the unit I2 bodily or they may be operated independently to correctly align the unit I2 with respect to the unit II.

The mechanism II which is removable from the base I8 as a unit is secured thereto by conveniently accessible thumb screws 93 (Fig. 5) engaged in threaded apertures 95 therein. The base I8 of the apparatus is provided with a shoulder 91 (Fig. 3) which serves accurately to locate the sub-base 98 of the recording unit II with respect to the guiding and feeding unit I2 when it is clamped in operative position by means of the thumb nuts 93. a

The aforementioned sub-base 98 of the unit II is integrally connected to an elongated tubular It will be understood that the tubular casing 99 may be a separate piece secured to the base 98 in any suitable manner. However the structure illustrated is simple to manufacture since the tubular casing, the connecting web and the sub-base may be constructed integrally by a casting operation, making the machine more rigid and eliminating any necessity of providing for delicate adjustments. A worn member or lead screw I82 is rotatably supported in the casing 99 upon antifriction bearings I83 of any suitable and well known type which are retained in position by set screws I84 and both ends of the casing 98 are closed by caps I85 secured in position by suitable fastening means I81. One of the caps I85 is apertured to permit protrusion of the extended portion I88 of the lead screw I82 to its point of connection with a flexible coupling I89 which is interposed between the lead screw and a driving motor II8. This motor H8 is connected by conductors III to a power source indicated at II2 which is of the same frequency as the source feeding the driving motor of the transmitter. A switch II4 may be provided for stopping the motor when desired. It will be apparent to those skilled in the art that any suitable means may be utilized for producing synchronism between the moving parts of the apparatus by which the picture is transmitted with the moving parts of the recorder. The

lead screw in the illustration is provided with a single thread II of a pitch such that one of the stylus holders H8 and a stylus H t secured thereto are advanced along the entire length of the platen 4I during the time in which the paper web 33 advances one hundredth of an inch.

Advancement of the paper web is accomplished through the gears already described including the worm 59 by means of a worm II8 integral with or secured to the shaft I82 which engages a worm wheel II8 secured on the shaft 81, the latter being joumalled in removable housing I28 secured adjacent th end of the housing as. It will be understood that the description previously given that as the lead screw I82 turns, rotation is imparted to the shaft 88 through the coupling composed of the parts 85 and 88 and the clutch 83.

The stylus holders II8 of which there are three in the specific embodiment selected for illustration are secured in any suitable manner to a belt I2I which passes over a pair of idler pulleys I22 journalled on studs I23 mounted in bosses I24 formed on the casing 98. A friction brake which exerts a constant drag on the idler pulley at the end of the scanning travel of the stylus is indicated by reference character I25. The latter is mounted on a resilient arm I28 which is secured to the end of the stud I23.

In the illustrative embodiment, the belt I2I is made up of several sections which are joined together by the stylus holders II8 serving as links as shown in Fig. 6 of the drawings. Adjacent ends of the belt I2I at the point of connection to a stylus holder II8 are provided with apertured members I21 secured to the belt by suitable fastening means I28. The upstanding central portions I29 of the stylus holders, which are roughly of T-shape as shown by Fig. 3 of the drawings, are apertured to receive pins I3I which engage in th apertures of the members I21. The arrangemeni; just described in specific detail provides a connection between the sections of the belt I2I and the stylus holders II8 which is flexible and does not interfere with the passage of the stylus holders II8 over the idler pulleys I22 but yet prevents angular movements of the stylus holders with respect to the platen 4I. It will be understood that while a preferred construction has just been described, nevertheless the jointed belt I2I may be an endless belt with the stylus holders I I8 secured thereto in any suitable manner as by riveting, welding-or soldering.

Each stylus holder I I8 has a stylus holding arm I32 clamped thereto between insulating pieces I34 and I38 by means of screws or other suitable fastening means I31. A flexible arm I38 is secured adjacent its end to the end of the arm I32 by screw means I39, the latter providing for adjustment of the position of the arm I38. As previously stated the stylus carrying arm I32 associated with each stylus holding member I I8 is insulated therefrom by means of insulating pieces I34 and I38 and signals are fed to the stylus H1, or received therefrom if the machine is modified to transmit, by means of a small collecting shoe I which is clamped against the arm I33 by means of the screws I31. Each collector shoe MI in turn cooperates with an angle-shaped collector rail I42 (Figs. 2 and 3) which is secured to the outer wall I43 of an elongated slot I44 communicating with the interior of the chamber 98. The collector rail I42 is insulated from the wall I43 by strips of insulating material I45 and I48. The

entire assembly comprising the collector rail I42 and the associated insulating strips are secured to the wall I43 by means of screws I41 which are.

ing the lead I48 at a desired point on the metallic structure of the machine.

The stylus holders I I8 are grooved as indicated at I5I and I52 so that they will be received and guided by the rod like rail members I53 and I54 located in the previously mentioned slot I44 (Figs. 3 and 5). Each stylus holder is provided with a driving member in the form of a stud I55 which enters the groove of the thread as the holder enters the slot I44.

The stylus holders are spaced on the belt so that the stylus points are separated a distance substantially equal to the length of the platen and the lead screw III is slightly longer than the platen so that one stylus engages the lead screw before another stylus, just completing a scanning operation, is disengaged from the lead screw. By keeping proper tension in the belt or by imposing friction on one of the pulley wheels, for example by the brake member I25 previously described, the effect of any slight shock occurring upon engagement of a stylus holder with the lead screw will be damped out. The flare at the entrance of the guiding slot I44 serves to allow a certain amount of leeway in the spacing oi the stylus points on the belt.

It is necessary that the stylus points on each of the styli be very accurately mounted so that they will all follow in the same horizontal plane and will be maintained in a fixed position with respect to the platen 4I. The accurate positioning of each stylus point is accomplished in a novel manner by apparatus forming part of thepresent invention and disclosed in Figs. 9 to 12 of the drawings. Referring to these figures and more particularly to Fig. 11, a jig or special fixture is disclosed comprising a base I58 which is provided with pins I51 adapted to locate the unit II after its removal from the base III for the purpose of performing the stylus locating operation. Holes I58 in the base I58 are spaced to accommodate the thumb screws 83 or their equivalent so that the unit II may be clamped in position on the base I58 in contact with the pins I51. The stylus supporting and shearing assembly I 59 holds a stylus in position temporarily until it is secured to one of the resilient stylus carrying spring members I38. The clamping assembly referred to comprises an upright supporting pillar I88 secured to the base I58 by a screw I8I. Two blocks I82 and I83 are adapted to be mounted on the pillar I88 which is formed at its upper end with V-shaped rails I84 which engage in grooves I88 in the underside of the block I82. The block I83 is provided with a V-shaped rail I81 which is adapted to fit in a V-shaped groove I85 formed on the upper surface of the block I82 and is recessed to provide a groove in which a cutting tool I88 is slidably retained by means of a plate I1I which is secured in position by fastening means I12. Dowel pins I13 are provided so that the plate I1 I is positioned accurately to clamp the end I14 of the stylus II1 against an arcuate groove I18 formed in a lip I11 extending upwardly from the block I82. The recess in the block I82 rearwardly of the lip I11 accommodates the plunger I88 when it is pressed or driven downwardly to clip oil! the end I14 of the stylus.

The blocks I62 and I63 are securely held during a cutting and soldering operation in the correct position with respect. to the unit II by a pair of tapered pins I18 passing through the body of the block I62 and tapering apertures in plates I19 which are rigidly secured to the upper portion of the pillar I60.

The unit II is provided with a locating pin I8I (Fig. 1) which may be engaged in a recess I82 in the lead screw I02. A spring I83 presses the pin I8I into the recess when a member I84 enters the slot I85 upon rotation of the pin I8I. In normal operation of the unit I I the pin is maintained in its retracted position by engagement of the member I84 against the flattened surface formed on the exterior of the chamber 59,

When a set of styli are to be fitted to the unit II it is removed from the base I of the recording machine and is placed on the base I56 to which it is secured by the thumb nuts 83 or equivalent fastening means. The assembly I59, in position on the base I58, holds a stylus firmly clamped in the groove I16 upon tightening the screw I68. One form of stylus which can be successfully used in the machine of the present invention comprises a core preferably of hardened steel I14 and a brass collar, the core of which can be clamped, as stated, in the groove I16 by the bar "I. The lead screw I02 is turned by hand or otherwise until one of the spring arms I38 is in a position to receive the stylus. The lead screw I02 is retained accurately in this position by turning the pin I8I until the member I84 enters the slot I85 permitting engagement of the end of the pin in the recess I82.

The stylus is then secured to the spring arm I38 by soldering or welding, the arm being in a position which need only be approximately correct. It is to be noted that since the arm I38 need not be positioned accurately, no delicate adjusting means are required to bring the arm I38 to a single definite position. After the stylus has been secured to the arm a small portion of its tip is then clipped oil by depressing the cutter bar I69 after which the clamping screw I68 is released and the pins I18 are withdrawn to allow the block I62 to be moved back. The following spring arm I38 carried by the belt I2| is then brought into approximately correct position before the block I60 by again turning the lead screw. In the embodiment shown the pitch of the lead screw is such that when it is rotated through ten turns. the belt is moved a distance equal to one third of its length, thus bringing the next spring arm into approximately the correct position. The soldering or welding and clipping operation is repeated following which the third stylus is installed on the remaining spring arm. In this way each stylus is accurately positioned in its holder and therefore all of the styli will traverse a single common line across the platen 4 I.

In operation of the apparatus to continuously record transmitted subject matter in facsimile. a roll 34 of suitable recording paper is secured between the paper holder spindles 36 and its end is fed into the machine by hand so that it lies in contact with the exposed surface of the member 28 and the driving belts 28, this operation being facilitated by turning the knob 45. The motor H8 is started by closing the switch II4 when the transmitter begins to scan transmitted subject matter and signals received over the line L will be recorded on the paper roll in successive lines by the styli I I1, each stylus tracing a single line and the next stylus tracing a line immediately beneath the previously recorded line. Apparatus similar to that disclosed in the above mentioned copending Ridings et a1. application, Serial No. 264,512 filed Mar. 28, 1939, may be employed to close the switch H4 to phase the machine with the transmitter. Atthe conclusion of reception of a given piece of subject matter the hand wheel 45 may be turned or the switch 1I closed to start the motor 66 until enough of the blank paper has been ejected so that it may be torn, using the edge of the member 3| as a uide.

Successive pieces of subject matter may be recorded automatically in spaced relationship upon the web 33 by using an arrangement similar to that disclosed in the application of Parrott et al.. Serial No. 161,356, filed August 28, 1937. The leads 10 of the motor 66 will then be connected to a circuit controller operated by spaced means on or in the paper web 33 to advance the paper at a rapid rate between recordings to avoid delay and save line time.

The apparatus of this invention may be operated with one or two styli by mounting the styli frictionally upon the belt I2I and operating the belt at a higher speed than the rate of travel of each stylus when it is driven by the lead screw. In this way the stylus which is traversing the platen will move at a relatively slow speed throughout the length of the platen, while the stylus which has completed a recording line is moving at a considerably higher speed through a distance which is approximately equal to twice the width of the platen H. In this form of the apparatus, an electrically or mechanically operated latch is preferably provided, along with means to effect its release, to permit the stylus holder, which has been brought into starting position, to be received in the slot I44 at the instant transmission of a new scanning line is begun While the invention has been described and explained in detail in connection with an illustrative embodiment thereof, it is to be understood that the invention may be embodied in other forms and, therefore, the invention is not limited except as indicated by the terms and scope of the appended claims.

What is claimed is:

1. In a facsimile recorder, a plurality of recording styli, a conveyor carrying said styli in spaced relationship, and screw-threaded means positioned to engage each of said styli in turn to move the same at a desired scanning speed.

2. In a facsimile recorder, a plurality of recording styli, a conveyor comprising an endless belt for carrying said styli in spaced relationship, and screw threaded means positioned to engage each of said styli in turn to move the same at a desired scanning speed.

3. In a facsimile recorder, a plurality of recording styli, paper holding and feeding means, means to receive and guide said styli in succession along said paper holding means, a conveyor carrying said styli in spaced relationship, and means positioned adjacent to said stylus guide means to move each of said styli in succession through said guide means at a desired scanning speed.

4. In a facsimile recorder, paper guiding and feeding means a plurality of stylus holders each carrying a stylus, a conveyor comprising an endless belt for carrying said styli in spaced relationship, guide means adjacent said paper feed means for receiving each of said stylus holders in turn, and screw-threaded means positioned to engage and drive a stylus holder entering said guide means.

5. A facsimile recorder comprising paper supporting and feeding means, a plurality of recording styli, only one of said styli being active at a given time for recording purposes, guide means for receiving and guiding said styli in succession across said paper supporting and feeding means, means for conveying an idle stylus from the exit end of said guiding means to the adit end, and means positioned adjacent said stylus guide means to impart scanning movement to said styli ing means.

7. In a facsimile recorder, a paper positioning platen, feed means for moving the paper over said platen, a recording stylus, means to guide said stylus on a scanning line across said platen in one path of movement, a conveyor for returning said stylus from the end of the scanning line to its initial point along a separate path, and means separate from said conveyor to impart movement to said stylus along said scanning line.

8. In a facsimile machine, a scanner comprising a conveyor, a plurality of stylus holders spaced at substantially equal intervals along said conveyor and secured thereto, a stylus on each of said holders, screw threaded means positioned to move each of said stylus holders in turn at a desired scanning speed, a pair of guide rails disposed adjacent said screw threaded means to guide said styli in succession along a predetermined scanning path, and a pair of oppositely disposed grooves formed in each of said stylus holders for cooperating with said pair of guide rails upon engagement of the stylus holder with the guide rails to hold the stylus holder in alignment with the rails, whereby the styli are guided in succession along the scanning path.

9. A device for locating a stylus on the stylus carrying member of a recording unit, comprising a base designed to receive said unit temporarily, means on said base to hold a stylus accurately in position with respett to a recording surface with which said unit is to be used in a recording machine and in position to permit accurate connection of said stylus to said stylus holder.

10. A device for locating a stylus on the stylus carrying member of a recording unit comprising a base designed to receive said unit temporarily, means on said base to hold a stylus accurately in position with respect to a recording surface with which said unit is to be used in a recording machine and in position to permit accurate connection of said stylus to said stylus holder and means associated with said first named means to trim said stylus to a desired recording length. Y

11. A device for locating a stylus on the stylus carrying member of a recording unit, comprising a base designed to receive said unit temporarily, a clamping device on said base to hold the stylus accurately in position with respect to a recording surface with which said unit is to be used, and in position to permit accurate connection of said stylus to said stylus holder and cutter associated with said clamping device to trim said stylus to a desired recording length.

12. In a facsimile recorder, a paper support, a paper feeding means for continuously advancing said paper over the support, an endless conveyor, a plurality of styli carried by said conveyor in equi-spaeed relation, means for guiding said styli in succession across said paper support, driving means for engaging each of said styli in turn to move the same across said paper support, and means for correlating said paper feed and stylus driving means.

13. In a facsimile scanning device, a platen,

means for advancing a sheet thereover, an endless conveyor, a plurality of scanning elements secured to said conveyor, means independent of said conveyor for engaging said scanning elements in succession to move the same in a scanning line across said platen and means including said conveyor for returning said scanning elements to the beginning of a new scanning line.

14. In a facsimile scanning device, a platen, means for advancing a sheet thereover, a plurality of scanning elements, a worm, means carried by each of said scanning elements for engaging said worm to cause the scanning elements to be moved in a scanning line across said platen, and means for returning certain of said scanning elements to one end of said platen in position to start a subsequent scanning movement while others of said scanning elements are being moved across said platen in said scanning line.

15. In a facsimile recorder, a paper platen, a paper feeding means for advancing the paper over said platen, a pair of guide rails spaced apart to provide a slot opposite said platen, a stylus carrying member formed to engage said rails, means to convey said stylus member to a point of cooperative engagement with said guide rails, and means operating independently of said conveying means to move said stylus member along a path defined by said rails.

16. In a facsimile recorder, a paper platen, a paper feeding means for advancing the paper over said platen, a conveyor carrying a plurality of styli spaced equi-distantly from each other, a housing positioned adjacent said platen providing a support for slidably receving each of said recording styli in turn, a worm in said housing, means to drive said worm, means to drive said paper feed means correlated with said worm driving means and a member positioned on each stylus to project into said housing for engagement with said worm when slidably supported by said housing. Y

GEORGE L. ERICKSON. RALEIGH J. WISE. 

